000060616 001__ 60616
000060616 005__ 20200221144243.0
000060616 0247_ $$2doi$$a10.1016/j.talanta.2015.09.060
000060616 0248_ $$2sideral$$a92313
000060616 037__ $$aART-2016-92313
000060616 041__ $$aeng
000060616 100__ $$aOrtega, E.
000060616 245__ $$aFluorescence of the Flavin group in choline oxidase. Insights and analytical applications for the determination of choline and betaine aldehyde
000060616 260__ $$c2016
000060616 5060_ $$aAccess copy available to the general public$$fUnrestricted
000060616 5203_ $$aCholine oxidase (ChOx) is a flavoenzyme catalysing the oxidation of choline (Ch) to betaine aldehyde (BA) and glycine betaine (GB). In this paper a fundamental study of the intrinsic fluorescence properties of ChOx due to Flavin Adenine Dinucleotide (FAD) is presented and some analytical applications are studied in detail. Firstly, an unusual alteration in the excitation spectra, in comparison with the absorption spectra, has been observed as a function of the pH. This is ascribed to a change of polarity in the excited state. Secondly, the evolution of the fluorescence spectra during the reaction seems to indicate that the reaction takes place in two consecutive, but partially overlapped, steps and each of them follows a different mechanism. Thirdly, the chemical system can be used to determine the Ch concentration in the range from 5×10-6 M to 5×10-5 M (univariate and multivariate calibration) in the presence of BA as interference, and the joint Ch+BA concentration in the range 5×10-6-5×10-4 M (multivariate calibration) with mean errors under 10%//a semiquantitative determination of the BA concentration can be deduced by difference. Finally, Ch has been successfully determined in an infant milk sample.
000060616 536__ $$9info:eu-repo/grantAgreement/ES/DGA/E74$$9info:eu-repo/grantAgreement/ES/MINECO/CTQ2012-34774
000060616 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/
000060616 590__ $$a4.162$$b2016
000060616 591__ $$aCHEMISTRY, ANALYTICAL$$b9 / 76 = 0.118$$c2016$$dQ1$$eT1
000060616 592__ $$a1.167$$b2016
000060616 593__ $$aChemistry (miscellaneous)$$c2016$$dQ1
000060616 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion
000060616 700__ $$0(orcid)0000-0002-7902-6005$$aDe Marcos, S.$$uUniversidad de Zaragoza
000060616 700__ $$0(orcid)0000-0002-3906-4576$$aSanz-Vicente, I.$$uUniversidad de Zaragoza
000060616 700__ $$aUbide, C.
000060616 700__ $$aOstra, M.
000060616 700__ $$aVidal, M.
000060616 700__ $$0(orcid)0000-0002-8973-5104$$aGalbán, J.$$uUniversidad de Zaragoza
000060616 7102_ $$12009$$2750$$aUniversidad de Zaragoza$$bDpto. Química Analítica$$cÁrea Química Analítica
000060616 773__ $$g147 (2016), 253-260$$pTalanta$$tTALANTA$$x0039-9140
000060616 8564_ $$s543391$$uhttps://zaguan.unizar.es/record/60616/files/texto_completo.pdf$$yPostprint
000060616 8564_ $$s81376$$uhttps://zaguan.unizar.es/record/60616/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint
000060616 909CO $$ooai:zaguan.unizar.es:60616$$particulos$$pdriver
000060616 951__ $$a2020-02-21-13:22:34
000060616 980__ $$aARTICLE